A monoclonal antibody with reactivity to asialo GM 1 and murine natural killer cells

Abstract

A monoclonal antibody (MAb) was prepared by the fusion of murine SP 2-O myeloma cells with BALB/cByJ spleen cells that were immunized with the glycolipid asialo GM 1 adsorbed to naked Salmonella. The specificity of the IgM antibody obtained was denned using various glycolipids, cell extracts and saccharides in ELISA assays and thin-layer chromatography (TLC) immunoblots. The non-reducing terminal galactose is the immunodominant residue for this antibody; however, there is undetectable reactivity to free galactose, galactosylceramide or compounds with an α-linked galactose. The SH-34 antibody specifically lyses asialo GM 1-expressing macrophages in the presence of complement and removes NK cells in vitro from spleen cell populations. When the specificity of the MAb was compared to that of a commercially available rabbit antiserum to asialo GM 1, it was found that both cross-reacted with GM 1 and asialo GM 3 at high antibody concns; however, the MAb did not bind asialo GM 2 while the rabbit antiserum showed substantial reactivity to this glycolipid. It is anticipated that this MAb will be useful for the study of murine and rat natural killer cells.